Ed Viesturs, known as "The Chevy truck of mountaineering," is one of the
world's pre-eminent high-altitude climbers and guides. Among his many
mountaineering accomplishments, he has reached the summit of Everest five
times, three of which were without the help of supplemental oxygen. His
experience has made him an astute observer of how humans are affected at high
altitudes.

NOVA: Do you prefer climbing with or without oxygen?

VIESTURS: For me, climbing without oxygen is much more enjoyable than climbing
with oxygen. Even though physically it's harder, I feel less encumbered by the
apparatus and oxygen mask on my face, which tends to be a little
claustrophobic. I breathe huge volumes of air up there and I often have to take
the mask off to get enough air. It's a weird sensation; even though it should
be easier with oxygen, for me it seems like it's easier without it. Whether
that's psychological or not I don't know.

NOVA: Do you think that you personally have a better ability at altitude than
others? If so, what do you think accounts for the difference?

VIESTURS: I think I have a better ability at altitude than other people. It
just happens to be genetic. Luckily, I'm in the right sport. I was born with
the genetics that allow me to climb at high altitudes, to acclimatize very well
and to deal with the altitude. It's a combination of genetics and physiology,
training and experience. Knowing how to climb at altitude, knowing how to climb
efficiently...it's a combination of all that. Also, being at the right place at
the right time on summit day, especially when you're climbing without oxygen—the weather has to be perfect, the snow conditions have to be reasonably good
and you have to have the right mental attitude. When all that stuff clicks on
that one day, then you can have a super summit day and really enjoy it. That's
what it's all about. Getting to the summit, having a great time, and coming
back to talk about it.

NOVA: Why do you use oxygen when you act as a guide for other climbers?

VIESTURS: It's a safety factor when you're guiding to be using oxygen. The
theory is that when you're guiding with oxygen, you're more mentally alert,
you're warmer. Typically, when you're guiding you're going quite slowly simply
because the clients are going at a normal, average pace. To go at that speed,
at that altitude, you need to stay warmer so oxygen provides you with the
warmth. It provides you with a little bit more mental acuity. When I'm climbing
without oxygen I constantly test myself mentally to make sure that I'm in
control, and if I feel that I'm not I should turn around.

NOVA: When you're guiding, how do you determine whether a client continues
climbing or not?

VIESTURS: When we're guiding here on Everest as in any guiding situation, we're
always assessing our clients every single day. Just because they got here and
paid their money does not mean that they get a chance to go to the summit. They
have to prove to us from camp to camp that they're capable of going to the next
higher camp. The whole process is an evaluation. That's the only safe way we
can do this. Mount Everest is the biggest mountain in the world and a lot of
people assume when they get here that they'll get a chance at the summit. We
try to educate them and tell them that they have to prove themselves and show
us that they're capable of making a summit attempt. The final day is the
hardest day by far, five times harder than any other day. If they flounder on
any of those other days, it shows us that they are not capable of going to the
summit.

NOVA: Can you describe for us a situation where you might determine that one of
your clients is being adversely affected by the altitude? What do you look
for?

VIESTURS: You always have to be evaluating and looking at their performance. We
look at their physical fitness and how they perform day to day and camp to
camp, how they react to the altitude, what they look like and how they feel
when they get to a certain camp. Do they still have enough energy to perform
basic tasks? Do they have enough energy to get down? Getting up is half of the
climb, getting down is the second and most important half of the climb. It's a
combination of things—their mental attitude and their acuity.

NOVA: Have you ever seen an example of one of your clients with cerebral or
pulmonary edema?

VIESTURS: I haven't seen any of our clients with cerebral edema but we have
seen people who have developed pulmonary edema. They show a great amount of
fatigue and they can't catch their breath. Their judgment is slightly impaired.
It doesn't only happen on the way up; sometimes it happens on the way down and
then becomes a strange event. When we're coming down and somebody is having
problems, you're thinking that they're very exhausted, or there is some sort of
respiratory problem going on.

VIESTURS: On a typical summit day we would get up at around 9 PM, and start
preparing to leave at 11 PM. It takes at least two hours to get enough fluids,
get a little bit of a snack, get dressed, put your boots on, get suited up, get
the oxygen systems ready and all that. We would be climbing then at 11 o'clock
at night with headlamps. The reason we do that is we want to get to the summit
and get down before it gets dark. It's much easier to go uphill towards a point
in the dark rather than coming down where everything spreads out in the dark.
We allow ourselves 12 hours to get to the summit. That is a reasonable amount
of time, that uses about two bottles of oxygen, and gives us one bottle of
oxygen to come down with (with plenty of safety margin). It should only take
perhaps four hours to come down, but by leaving at 11 o'clock we then have six
hours to get down before it gets dark. If anything happens, we have plenty of
time.

You might think that if you stretched the summit day longer than 12 hours, say
by bringing more oxygen, you could climb for 15-16, 18 hours but by then people
would be very tired, and it wouldn't give you any margin of safety for coming
down. So we begin the ascent around 11 PM and we're about halfway to the summit
when the sun rises and it's a really spectacular day. We crest the Southeast
Ridge and we can see Makalu and Kanchenjunga. From there we continue on the
Ridge, over the South Summit. You have to be a good climber to climb Mt.
Everest safely. It's steep, it's exposed, there's rock, there's snow, there's
ice. Not anybody can just put on an oxygen mask and climb Everest. It's very
dangerous to assume that.

The last 300 feet to the summit you would think is only 300 feet but at those
altitudes (at 28,700 feet) the amount of effort that you need is exponentially
increasing in difficulty. It is not a gradual increase in difficulty. It is an
exponential increase. The last 300 feet take one to two hours to climb. It is
the steepest and most rugged terrain of the whole climb. From the South Summit
you traverse a knife-edge ridge that is vertically exposed on both sides so you
have to be very careful. The Hillary Step at 28,800 feet is a vertical snow and
rock step that you have to climb. At those altitudes, it is quite physically
difficult. Once you are above that, it is probably 200 yards to the summit at
about a 30-degree snow slope.

It doesn't seem difficult. Down here it would probably take 10 minutes to walk
that, but up there it is a very slow and arduous process. You breathe six to
eight times and then you take another step and then you breathe six or eight
times. Often you just think about taking another step, you breathe six or eight
times and then you finally take that step. It's quite a physical and mental
effort just to think about taking each individual step. That's how you have to
break the summit day down. You can't look at the whole ascent. You have to
break it down into small sections and into tiny little steps. You put your mind
to taking each step and slowly you chew away and finally you are on the summit.

On a good day, I've spent as long as an hour and a half on the top. If there is
good weather, if we have plenty of time, we hang out for an hour or so and take
pictures. If it is a bad day, we might spend five minutes up there. It's hard
to really relax. You're happy that you're there but you can't really relax and
let your guard down because you know that you still have to get down. I always
tell people that getting to the summit is optional but getting down is
mandatory. A lot of people forget the fact that climbing down is often as hard
as climbing up. They use all their energy to get to the summit and then that's
it. And for me, it doesn't count if you don't get down. It's very important to
remember that.

VIESTURS: The descent is quite arduous. People are tired. You're physically
spent. You have to think about what you are doing. You can't just stagger and
slug your way down. You have to be very careful. You don't want to fall. A lot
of accidents in mountaineering occur on the descent. It's because people get to
the summit and totally let down their guard; they have used all of their energy
just to get to the top. We're constantly evaluating our clients to make sure
that not only can we get them up but that they have enough energy to get down.
If at any point on the ascent it looks like they are starting to become very
tired we turn them around and take them down. It is more important for us to
get them home then to get them to the summit.